Sam’s Club, the membership-only warehouse unit owned by Walmart, is laying off about 2,300 employees in its largest wave of job cuts in four years, the Wall Street Journal reports. It is one of several retail chains to announce steep job cuts in January.

The layoffs come amid an effort to compete with rival Costco and online competition like Amazon, which has its own club-like service called Amazon Prime. Assistant managers will comprise nearly half the layoffs as the unit looks to slim down its managerial staff.

Sam’s Club joins a a growing list of major retailers announcing job cuts this year. JC Penney said last week it will close 33 stores and cut 2,000 employees, and Macy’s announced earlier in the month that it would layoff 2,500 workers. Target is also laying off 475 workers and has eliminated 700 vacant positions over the last six months.